0 


U.   S.    DEPARTMENT   OF   AGRICUITL 

OFFICE  OF  EXPERIMENT  STATIONS— FARMERS'  INSTITUTE  LEl 

A.  C.  TRUE,   Dire. 


SYLLABUS 


ILLUSTRATED  LECTURE 


ON 


THE  CARE  OF  MILK 


BY 


R.  A.  PEARSON,  M.  S., 

Con. 


WASHINGTON: 

GOVERNMENT   PRINTING   OFFICE. 

1904. 


L 


735. 


U.    S.    DEPARTMENT    OF    AGRICULTURE 

OFFICE  OF  EXPERIMENT  STATIONS-FARMERS'  INSTITUTE  LECTURE  NO.  1. 
A.  C.  TRUE,  Director. 


SYLLABUS 


OF 


ILLUSTRATED  LECTURE 


ON 


THE  CARE  OF  MILK 


BY 


R.  A.  PEARSON,  M.  S. 

Cornell  University,  Ithaca,  N.  V. 


WASHINGTON: 

GOVERNMENT    PRINTING    OFFICE. 
T904. 


I'KHI  \TORY  NOTE. 


This  syllabus  of  a  lecture  upon  The  Care  of  Milk,  by  K.  A.  Pearson, 
M.  S.,  Professor  of  Dairy  Industry  in  the  School  of  Agriculture  of  Cor- 
nell University,  Ithaca,  N.  Y..  is  accompanied  by  44  lantern  Blidee 

illustrating  the  topic.  The  syllabus  and  views  have  been  prepared  for 
the  purpose  of  aiding  farmers'  institute  lecturers  in  their  presentation 
of  this  subject  before  institute  audiences. 

The  numbers  in  the  margins  of  the  pages  of  the  syllabus  refer  to 
similar  numbers  on  the  lantern  slides  and  to  their  legends  as  given  in 
the  Appendix.  Those  in  the  body  of  the  text  refer  to  corresponding 
numbers  in  the  list  of  authorities  and  reference-. 

In  order  that  those  using  the  lecture  may  have  opportunity  to  fully 
acquaint  themselves  with  the  subject,  references  to  its  recent  literature 
are  given  in  the  Appendix. 

John    Hamilton. 
Farmers  Institute  Specialist. 
Recommended  for  publication. 
A.  C.  True,  Director. 

Publication  authorized. 

James  Wilson,  Secretary  of  Agriculture. 

Washington,  D.  C,  Octoba  1,  1904. 

(2) 


THE  CARE  OF  MILK. 

By     R.    A.     I'KARSON.    M.    S. 

The  value  of  the  milk  and  milk  products  produced  in  the 
United  States  in  the  last  census  year,  1900,  is  given  by  Alvoid        1    /  9 
HifiiEfiftfij?1  fjfjSfil  (1— p  H)  a     This  is  greater  than  the  value  of  ^L<?£^f   vun*<* 
the  metallic  minerals  produced  in  the  same  year  and  including  t^^^^kfe^ 
pig  iron,  silver,  gold,  copper,  lead,  zinc,  and  other  metals.     It  $/ s^^£&  <*~ 
is  also  groatJcy  tyn . *fne  total  value  of  nonmetallic  minerals  1)t^tc^^/)  ^ 
produced  in  190jjJ/and  including  bituminous  coal,  Pennsylva-  juxJbCvv*- <*&<?('  &-p- 
nia  anthracite,  petroleum,  natural  gas,  brick  clay,  cement,  etc.  f  &S£>  3# '/,  <£  ^ 

Undoubtedly  the  most  important  use  of  milk  is  in  its  natu- 
ral form  as  a  human  food  or  as  "market  milk"  (2 — p.  5)  and 
(3— p.  3).     Almost  every  individual  of  our  population  uses       *i 
more  or  less  milk  and  often  depends  largely  upon  it  for  suste- 
nance.    But  most  of  the  milk  produced  is  used  for  making- 
butter,  while  a  comparatively  small  amount  is  used  for  mak-       ;> 
ing  cheese.     It  is  estimated  that  the  amount  of  milk  U3cd  as  Josi^-cC^c^tC* 
U-markct  milk"  (a  email  part  of  it  condensed)  is  equivalent  w^dL*** ^^nyc^ 
frho  pr^du^t^r*  ^  about   7,fi00,000  rnwv,  thn   milk  ua»d  f rtr  ^^^  t ?  '  o  ^^^ff/ 

fritW  rY,QVjng  pqim.lg    thp.  prnHiiPtinn-jif   0^700^000  rouu  mid  £^££  V^ 

for  ohccoo  mailing  800/000  cuws,  making  a  total  of  abuiir^<g-^&     /3SLp*U** 
18,100,000  tuwa  in  the  United  3tates. —  fc^t^^  <n^^A^^Xc 

The  profitable  production  of  milk  involves  two  ver}'  differ-  (TJaA^J&Jdh  /?/  & 
ent  kinds  of  problems:  First,  how  can  the  farmer  form  a  herd  /        rjz^e^tjL+t 
that  will  give  in  the  milk  pail  liberal  returns  for  the  cost  of  "     j  q  //jj^t^S  c2, 
feed  and  care  ?  and,  second,  how  should  the  milk  be  handled^^v? 
to  keep  it  in  the  best  marketable  condition?  t^£o 


I.   (a)  As  is  well  known,  there  are  great  differences  in  the   , 
value  of  cows  as  milk  producers.     In  the  same  herd  there  areA^o^xi^T>f^^^^-^ 
often  found  individuals  that  do  not  yield  enough  to  pay  foi  2i^J^J^^  uhcte* 
their  feed,  and  others  that  yield  enough  milk  to  pay  for  feed     ^   [    <>  S  <?  cx-jZu 
and  care  and  leave  a  handsome  profit  for  the  owner  (4 — p.  45). 
All   stages   between   these   extremes   are  represented.     The 
easiest  way  to  improve  the  average  of  a  herd  is  to  get  rid  of 
the  unprofitable  cows,  and  the  two  best  aids  for  this  are  milk 
scales  and  a  Babcock  tester,  with  a  carefully  kept  record  of       « 
each  cow  and  a  determination  to  relentlessly  cull  all  unprom- 
ising stock  (5— p.  8).     Some  of  the  unprofitable  cows  can  be       <> 

« Meaning  reference  book  or  bulletin  No.  1,  page  44. 

(3) 


found  without  these  aids,  but  the  best  judges  arc  liable  to 
make  mistakes  in  picking  them  out.  This  is  largely  because 
the  richness  of  milk  can  not  be  told  by  its  appearance. 

(6)  Very  many  dairy  herds  would  show  better  returns  if 
they  were  \'n\  better.     Cows  giving  milk  are  performing  hard 
7  work  and  must  be  well  nourished,     [f  the  ration  is  small,  but 

little  of  il  will  be  available  for  making  milk  after  the  accessary 
requirements  of  supporting  life  are  satisfied.  And  care  must 
be  taken  to  have  the  ration  Include  the  proper  constituents 
protein,  carbohydrates,  and  fat  for  making  milk,  repairing 
tissue  wastes,  and  producing  bodily  heat  (6).  It  is  accessary 
to  carefully  study  the  markets  and  the  possibilities  of  the 
farm  to  be  able  to  obtain  feed  most  cheaply. 

(c)  Health  and  comfort  of  the  cow  and  regularity  and  kind- 
ness in  her  care  are  also  prime  requisites  for  the  economical 
production  of  milk  (5 — pp.  10  and  18). 

1 1.  The  losses  suffered  by  dairy  farmers  because  of  improper 
methods  of  handling  milk  amount  to  a  vast  sum.  Milk  is  in 
ideal  condition  when  first  secreted  in  the  udder  of  the  healthy, 
well-kept  cow,  but  if  it  is  not  properly  cared  for  it  will  lose  a 
part  or  all  of  its  market  value  soon  after  it  is  taken  from  the 
udder.  The  changes  of  milk  are  due  to  bacteria  and.  if  the 
dairyman  understands  somewhat  the  nature  and  habits  of 
these  little  creatures,  he  is  greatly  aided  in  protecting  himself 
against  their  depredations  (7 — Chap.  I)  and  (8 — (hap.  [). 
Bacteria  are  very  abundant  in  nature.  They  are  minute1  veg- 
etable organisms  and  many  kinds  of  them  are  useful,  but 
some  are  objectionable  and  even  dangerous.      Numerous  dif- 

S  ferent  kinds  have  been  found  in  milk  and  some  of  them  have 

been  carefully  described  and  illustrated.  Souring  is  the  most 
common  bacterial  change  of  milk  and  is  due  to  the  presence 
and  activity  of  a  large  number  of  germs  called  lactic-acid 
germs,  that  change  the  sugar  of  milk  into  acid   (9).      Some 

1)  times  milk  undergoes  putrefactive  changes,  or  it  may  become 

stringy,  or  bitter,  or  red,  or  blue,  or  it  may  be  affected  in  many 
other  ways,  each  different  kind  of  change  or  fermentation 
being  due  to  the  growth  of  large  numbers  of  some  kind  of  bac- 
teria. Besides  the  bacteria  that  produce  marked  changes  in 
milk,  forms  sometimes  get  into  it  that  retain  their  life  but  do 
not  multiply  and  produce  changes,  and  others  that  grow  more 
or  less  rapidly  but  without  producing  noticeable  changes, 
although  they  make  the  milk  unwholesome.     Unfortunately 


these  latter  kinds  sometimes  include  germs  that  cause  disease, 
and  if  they  once  get  into  a  supply  of  milk  they  may  produce  1  <* 
sickness  and  even  death  to  the  consumer.  The  diseases  most 
liable  to  be  thus  carried  by  milk  are  typhoid  fever,  diphtheria, 
and  scarlet  fever  (8 — Chap.  V).  To  be  sure,  these  diseases  are 
not  often  transmitted  by  milk,  but  they  have  been  carried  in 
this  way  often  enough  to  prove  that  the  possibility  and  the 
danger  exist.  The  dairyman,  then,  should  produce  and  han- 
dle his  milk  in  such  a  way  as  to  exclude  all  disease-producing 
or  pathogenic  bacteria  and  as  many  as  possible  of  the  forms 
that  cause  milk  tp  sour  or  otherwise  deteriorate  in  value. 

How  do  bacteria  get  into  milk  and  how  can  they  be  exr 
eluded?  (7— Chap.  Ill),  or  (8— Chap.  II),  or  (10— p.  13). 
If  the  udder  is  diseased  it  may  be  the  source  of  a  large  num- 
ber of  objectionable  bacteria.  But  a  small  number  of  bac- 
teria are  in  the  milk  in  the  healthy  udder.  They  enter 
through  the  orifice  of  the  teat  and  become  permanently  estab-  1  1 
lished  in  the  teat,  milk  cistern,  and  ducts.  They  are  most 
abundant  in  the  first  few  streams  drawn,  and  in  dairies  where 
every  possible  precaution  is  taken  to  exclude  bacteria,  it  is 
the  rule  to  discard  the  first  few  streams  from  each  teat.  Some 
recent  investigations  seem  to  indicate  that  the  contamination 
of  milk  from  this  source  is  not  as  serious  as  once  supposed. 

The  chief  source  of  bacteria  in  milk  is  foreign  matter  which 
finds  its  way  into  milk  in  greater  or  less  quantities  according 
to  the  care  taken  to  exclude  such  contamination.  Small  par- 
ticles of  soil  or  manure,  hairs,  dust,  old  milk,  impure  water, 
etc. — all  are  carriers  of  bacteria. 

(a)  The  cows  should  be  kept  clean.  This  can  be  managed 
easily  if  the  barnyard  and  stable  are  kept  reasonably  clean.  12 
The  stable  air  should  be  as  free  as  possible  from  dust;  the  13 
room  should  have  a  tight  ceiling,  no  hay  nor  straw  should  be  14 
stored  in  it,  no  dry  feed  should  be  given  at  or  just  before  milk-  1 5 
ing  time,  and  everything  which  tends  to  produce  dust  should 
be  avoided  as  much  as  possible. 

(6)  vStables  should  be  well  lighted  and  ventilated  both  for 
cleanliness  and  the  health  of  the  animals.     The  mistake  is     16 
often  made  of  constructing  cow  stables  with  too  few  windows 
or  none  and  without  provision  for  ventilation.     The  newest 
idea  is  to  admit  an  abundance  of  light  and  to  have  ventilating     \  7 
shafts  to  conduct  away  the  most  impure  air  which  is  nearest     1  § 
the  floor  and  others  to  admit  fresh  air  near  the  ceiling  (11 — 


2  5 


p.  354  '.      Hut  thi^  system  will  no1  work  when*  there  are  open- 
1  0  ingS  througb  which  the  air  can  pass  outward  or  inward  with- 

out control.     It  is  a  serious  mistake  to  think  that  the  precau- 
2Q  tions  necessary  in  the  stable  for  the  production  of  pure  milk 

require  the  construction  of  a  costly  building  (\'2     p.  •• 

(c)  Before  milking,  the  cow  should  be  cleaned,  especially 
21  those  parts  from  which  dirt  might  fall  into  the  milk  pail.  A 
'-'-             Petri  plate  (7      p.  41)  exposed  under  a  COW  whose  udder  and 

surrounding  parts  are  being  more  or  less  shaken  by  the  action 
of  milking,  indicates  the  large  number  of  bacteria  dislodged 

o;;;  at  this  time.      It  does  not  require  much  time  t<>  brush  oil"  the 

COWS  and   to  wipe  the  udder  and   Hanks  with   a   damp    cloth 

•j  j  before  milking.     Eraser  reports  (13 — p.  593)  that  22  tin* 

much  dirt  will  fall  from  an  udder  slightly  soiled  as  from  one 
that  has  been  washed,  and  when  the  udder  is  muddy  the 
quantity  is  90  times  as  great.  Between  the  cleaning  and 
milking  a  cow  can  he  kept  Btaiiding  by  a  simple  device  con- 
sisting of  a  chain  attached  to  one  side  of  the  stanchion,  with 
a  hook  on  the  end,  to  be  fastened  to  the  other  side  of  the 
stanchion  under  the  cow's  neck 

(d)  But  with  all  the  care  that  can  be  exercised  some  dirt 
and  bacteria  will  be  constantly  falling  where  milking  is   in 

'Hi  progress.      The  common  milking  pail  has  a  wide  open  top  to 

catch  a  large  amount  of  this  falling  material.  The  amount 
falling  into  the  milk  pail  can  be  greatly  reduced  by  the  use  of 
a  pail  with  a  small  top  (14 — p.  5).  Tf  the  diameter  is  reduced 
to  one-half,  then  the  opening  will  be  reduced  to  one-fourth  the 
usual  size.  This  can  be  easily  done  by  using  as  the  milk  pail 
an  ordinary  10-quart  serving  pail  having  an  opening  about  6 
inches  in  diameter.  The  opening  can  he  still  further  reduced 
by  the  use  of  a  special  form  of  serving  pail,  one  having  a  visor 
attached  at  one  side  of  the  opening  and  projecting  over  a  pari 
of  it.  When  the  pail  is  in  use  the  visor  is  on  the  upper  side, 
away  from  the  cow,  and  the  more  the  pail  is  tipped  toward 
the  cow  the  more  the  opening  is  protected  from  falling  dirt. 
If  the  visor  is  high  the  opportunity  for  dirt  to  enter  while  the 
pail  is  in  use  is  reduced  to  almost  nothing.  This  kind  of 
sanitary  milking  pail  seems  to  have  some  advantage-  over 
those  in  which  cloth  strainers  are  used.  Experience  shows 
that  milkers  can  soon  become  accustomed  to  this  style  of 
pail,  and  the  difficulty  of  milking  into  a  small  opening  is  not 
:i-  serious  a-  at   first   supposed.     A  simple  experiment  will 

28  show  that  milk  can  he  easily  drawn  into  a  small  opening. 


21 


View. 

(e)  So  far  as  possible  sharp  angles  should  be  avoided  in     k*9 
milk  utensils  because  of  the  difficulty  in  cleaning  such  places. 

(/)  Persons  who  milk  cows  and  handle  milk  should  be  in 
good  health  and  under  no  circumstances  come  in  contact  with 
a  person  suffering  from  a  contagious  disease.  A  special  gar-  ;{(> 
ment  should  be  worn  when  milking  or  handling  milk,  and 
hands  should  be  carefully  cleaned  and  kept  dry.  In  dairies 
where  every  precaution  is  taken  to  keep  the  milk  pure  it  is 
customary  for  attendants  to  wear  white  overall  suits  that  are 
cleaned  and  sterilized  daily.  This  would  be  impracticable  in 
the  average  dairy,  but  a  special  garment  could  be  used  for 
milk  work  and  cleaned  at  frequent  intervals  without  a  notice- 
able increase  in  the  operating  expenses.  If  milkers  are  ex- 
pected to  keep  their  hands  clean,  provision  for  this  should  be  g-j 
made  in  or  near  the  stable. 

(g)  Immediately  after  milk  is  drawn  it  should  be  cooled  to 
below  50°  F.  to  prevent  the  multiplication  of  the  bacteria 
that  have  found  their  way  into  it  (7 — p.  47),  or  (8 — p.  100).     ~^ 
This  can  be  done  by  pouring  the  milk  over  a  cooler  or  by  stir- 
ring it  in  cans  set  in  cold  water.     If  the  milk  has  been  taken 
in  a  cleanly  manner  and.  there  is  no  bad  flavor  on  account  of 
weeds  or  other  flavor  producers  in  the  cow's  ration,  then  aera- 
tion is  not  necessary.     A  good  glass  floating  thermometer     33 
should  always  be  at  hand.     With  the  aid  of  Petri  plates  the 
effect  of  different  temperatures  upon  the  rapidity  of  bacterial 
increase  in  milk  is  clearly  shown.     They  increase  very  slowly     34 
below  50°  F. 


35 


(h)  Milk  should  not  be  handled  or  stored  in  the  stable  (13 — 
p.  606).  A  separate  milk  house  can  be  built  at  small  cost,  or 
if  this  is  impracticable,  a  room  can  be  partitioned  off  in  the 
corner  of  the  stable  most  distant  from  the  barnyard.  It  is 
well  to  have  but  one  entrance  to  this  room,  and  place  it  so 
that  a  person  entering  from  the  stable  will  have  to  first  pass 
out  of  doors. 

Inside  the  milk  room  there  should  be  smooth  walls  and  no     3<j 
unnecessary  shelves,  nooks,  and  corners  for  catching  dust.         37 

If  milk  is  to  be  bottled,  this  can  be  done  quickly  and  easily     38 
by  hand  if  a  small  amount,  or  with  a  special  bottling  machine.     39 

(i)  The  proper  cleaning  and  sterilization  of  utensils  is  a 
matter  of  great  importance  (7 — p.  27).  When  there  is  much 
of  this  to  be  done,  special  equipment  is  necessary,  but  thor-     40 


• 

4 1  ough  work  can  be  performed  by  hand  and  with  the  simplest 

equipment.  It  is  a  great  help  to  have  a  boiler  and  steam  for 
sterilizing,  but  even  without  this  as  good  results  can  be 
obtained  by  the  use  of  boiling  water.  Before  sterilizing,  all 
utensils  should  be  cleaned  by  riming  in  warm  water,  thorough 

w  mailing  in  hot  water,  and  rinsing  in  clean  warm  or  cold  water 

12  Milk   hauled   to  the  station  or  factory   in   hot    weathei 

should   he  covered   to  protect    it    from  heat    (10      J).   35).      In 

\:\  some  places  wooden  casks  are  used  for  carrying  milk,  hut 

metal  or  glass  is  much  better  because  easier  cleaned. 

Dairy  literature  is  chiefly  in  the  form  of  a  small  Dumber  of 
4  1  hooks  and  bulletins  issued  during  the  last  few  years,  besides 

some  periodicals  that  give  all  or  a  part  of  their  Bpace  to  dairy 
subjects. 


APPENDIX. 


LANTERN   SLIDES. 

No.  of  Legends. 

view. 

1.  The  distribution  of  milch  cows  in  the  United  States. 

From  I*.  S.  Dept.  Agr.,  Bureau  of  Animal  Industry  Bui.  55,  PI.  I. 

2.  The  most  important  use  of  milk  is  as  a  human  food. 

Original. 

3.  Most  of  the  milk  produced  is  used  for  making  butter  and  cheese. 

Original. 

4.  Table  showing  the  annual  production  and  creamery  value  of  the  milk  of  each  cow 

tested  through  one  period  of  lactation. 
From  Wisconsin  Sta.  Bui.  75,  p.  23. 

5.  Milk  scales  and  the  Babcock  milk  tester. 

Original. 

6.  Diagram  showing  composition  of  milk. 

From  Wisconsin  Sta.  Bui.  61,  fig.  2. 

7.  Table  giving  the  average  digestible  nutrients  in  American  feeding  stuffs. 

Original. 

8.  A  variety  of  bacteria  liable  to  be  found  in  milk. 

1  and  2,  typhoid  bacillus  (Pfeiffer) ;  3,  pus  and  pus  cocci;  4,  B.  dysenterix  (Shigar) ;  5,  Proteus 
vulgaris;  6,  Clostridium  butyricus;  7,  9,  10,  11,  types  of  common  lactic  bacteria  (Conn);  8,  a 
coccus  without  influence  on  milk  (Conn);  12,  13.  14,  three  bacilli  producing  slimy  milk  (fig.  12, 
Marshall;  figs.  13  and  14,  Conn);  15,  16,  17,  18,  19,  types  of  liquefying  and  putrefying  bacteria 
which  digest  the  casein  (Conn) . 

From  H.  W.  Conn's  "Bacteria  in  Milk  and  Its  Products,"  fig.  16. 

9.  Ropy  milk. 

From  New  York  Cornell  Sta.  Bui.  195,  fig.  5. 

10.  Graphic  representation  of  a  milk  epidemic  of  scarlet  fever. 

A,  B,  and  C  are  milk  producers.  1  and  2  are  milk  distributers.  The  circles  represent  house- 
holds, the  inclosed  dots  cases  of  scarlet  fever.  Upon  farm  A  there  was  a  case  of  scarlet  fever. 
The  diagram  shows  that  milk  from  farm  A  gave  rise  to  scarlet  fever  even  when  mixed  with 
other  milk. 

From  H.  W.  Conn's  "Bacteria  in  Milk  and  Its  Products,"  fig.  23. 

11.  The  interior  of  the  cow's  udder. 

From  New  York  Cornell  Sta.  Bui.  158,  PI.  III. 

12.  A  badly  kept  barnyard. 

From  Illinois  Sta.  Bui.  84,  fig.  7. 

13.  A  well  kept  barnyard  means  much  for  the  cleanliness  of  the  milk. 

From  Illinois  Sta.  Bui.  84,  fig.  8. 

14.  The  air  in  a  stable  such  as  this  is  constantly  filled  with  dust. 

From  Illinois  Sta.  Bui.  84,  fig.  18. 

15.  Tight  ceiling  and  cement  floor,  sanitary  throughout. 

From  S.  L.  Stewart's  Brookside  Dairy,  Newburgh,  N.  Y. 

(9) 


10 


iti.     (  ow  stable  ami  dairy  house  improperly  located  and  consl meted  and  poorrj  cared  for. 

pybm  U,  8.  Dept.  Agr.,  Farmers'  Bui.  63,  fig.  2. 
17.     A  well  lighted,  modern,  sanitarj  Btable. 

From  Walker-Gordon  Laboratory  (  o.,  Boston,  Ma- 
is.   The  ventilating  shaft  removes  the  impure  air  which  i-  Dearest  the  Boor. 

From  Illinoi-  Sta.  Bui.  84,  fig.  21. 
nt.     Uncontrolled  ventilation. 

Original. 
_'u.    The  barn  of  a  small  fanner  who  made  certified  milk. 

Prom  S.  D   Belcher's  "(lean  Milk. 
21.     The  flanks  a-  u..||  as  the  udder  should  !><•  clean. 

( Original. 
Fig.  l.     Petri  plate  exposed  two  minutes  out  of  doors.    Contains  6  colonies. 
Fig.  2.     Petri  plate  exposed  two  minutes  in  barn.    Contains  111  coloniea 

Fig.  A.      Petri  plate  exposed  two  minutes  under  COW  being  milked.      Contains  l.sm 

colonies. 

I  il-'s  l.  2,  and  '■•  <h<>\\  the  extent  of  the  cent  a  mi  nation  to  which  milk  [s  exposed  from  the  dust 
ol  ih''  barn  and  the  droppings  from  the  belly  ami  adder  of  the  oow. 

From  "Medical  Record.-'  March  28,  1896. 

0W8  should  1m>  kept  clean. 

From  C.  S.  Dept.  Agr.,  17th  An.  Kpt.  Bureau  of  Animal  Industry,  PL  XXXV. 

"_M.      The  amount  of  dirt  caughl  under  muddy  and  slightly  soiled  udders,  before  and  after 

cleaning. 

From  Illinois  Sta.  Bui.  84,  fig.  11. 

25.  A  chain  under  the  neck  of  the  cow  will  keep  her  from  lying  down  after  being  cleaned 

and  before  being  milked. 
Original. 

26.  The  wide-top  pail  catches  too  many  falling  particles  of  dirt  and  dust. 

( higinal. 

27.  The  common  milking  pail:  one  with  smaller  top:  and  the  Freeman  pail. 

Original. 
Milk  can  be  drawn  into  a  small  opening. 
Original. 

29.  The  wrong  and  the  right  kind  of  a  milk  pail. 

A.  the  ordinary  type  of  pail  showing  sharp  angle  between  sides  and  bottom;  B.  the  same 
properly  flushed  with  solder  bom  to  facilitate  thorough  cleaning.  The  lower  figure  represents 
a  joint  as  ordinarily  made  in  tinware.  The  depression  affords  a  place  of  refuge  for  bacteria  from 
which  they  are  not  readily  dislodged.     This  open  joint  should  be  filled  completely  with  solder. 

From  H.  L.  Russell's  "Dairy  Bacteriology.' 

30.  A  special  garment  for  milking. 

Original. 
3L      A  place  where  the  milker-  can  wash  his  hands. 
Original. 

32.  (  boling  the  milk. 

From  Tennessee  Sta.  Bui.,  Vol.  XV,  No.  I,  frontispiece. 

33.  Glass  floating  thermometer. 

Original. 

34.  Showing  the  effect  of  temperature  upon  bacteria  growth. 

a,  a  single  bacterium;  i>.  its  progeny  in  twenty-four  hours  in  milk  kept  at  .50°  F..  5  bacteria; 
progeny  in  twenty-four  hours  ih  milk  kept  at  70°  P.,  7.V1  bacteria.     Figures  taken  from 
el  oal  experiment. 
From  II.  W,  Conn's  •Bacteria  in  Milk  and  Its  Products."  fig.  20. 


11 


No.  of 
view. 

35. 

36. 
37. 
38. 
39. 
40. 
41. 
42. 
43. 


A  separate  milk  house. 

From  Illinois  St  a.  Bui.  84,  fig.  3? 
Smooth  walls  in  the  milk  room. 

Original. 


44. 


Dust  traps  in  the  milk  room  should  not   be  permitted. 

Original. 
A  cheap  and  clean  way  of  bottling  milk. 

From  Illinois  Sta.  Bui.  84,  fig.  42. 
Students  receiving  instruction  in  milk-bottling  in  a  dairy  school. 

Original. 
A  pressure  sterilizer. 

From  S.  L.  Stewart's  Brookside  Dairy,  Xewburgh,  X.  Y. 
Washing  and  sterilizing  milk  cans. 

From  Illinois  Sta.  Bui.  84,  fig.  28. 
Farmers  delivering  milk  to  the  shipping  station. 

From  S.  D.  Belcher's  •' Clean  Milk." 
From  the  mountains — carrying  milk  to  the  cheese  factory  in  Switzerland. 

From  U.  S.  Dept.  Agr.,  17th  An.  Rpt.  Bureau  of  Animal  Industry,  PI.  XLVI, 
fig.  1. 
Some  recent  books  and  bulletins  upon  milk  production. 

Original. 


REFERENCES. 

1.  Statistics  of  the  Dairy.     U.  S.  Dept.  Agr.,  Bureau  of  Animal  Industry  Bui.  55. 

2.  Facts  about  Milk.     U.  S.  Dept.  Agr..  Farmers'  Bui.  42. 

3.  Milk  as  Food.     U.  S.  Dept.  Agr.,  Farmers'  Bui.  74. 

4.  Studies  in  Milk  Production.     Wisconsin  Sta.  Bui.  102. 

5.  The  Dairy  Herd:  Its  Formation  and  Management.     U.  S.  Dept.  Agr.,  Farmers' Bui.  55. 

6.  The  Feeding  of  Farm  Animals.     U.  S.  Dept.  Agr.,  Farmers'  Bui.  22. 

7.  Dairy  Bacteriology.     By  H.  L.  Russell.     The  Author.  Madison,  Wis. 

8.  Bacteria  in  Milk  and  Its  Products.     By  H.  W.  Conn.     P.  Blackiston's  Son  &  Co., 

Philadelphia. 

9.  Souring  of  Milk.     U.  S.  Dept.  Agr.,  Farmers'  Bui.  29. 

10.  The  care  of  Milk  on  the  Farm.     U.  S.  Dept.  Agr.,  Farmers'  Bui.  63. 

11.  Physics  of  Agriculture.     By  F.  H.  King.     The  Author,  Madison.  Wis. 

12.  Clean  Milk.     By  S.  D.  Belcher.     The  Hardy  Publishing  Co..  New  York. 

13.  Dairy  Conditions  and  Suggestions  for  Their  Improvement.     Illinois  Sta.  Bui.  84. 

14.  The  Covered  Pail  a  Factor  in  Sanitary  Milk  Production.     Connecticut  Storrs  Sta. 

Bui.  25. 

Some  other  boohs  a?id  bulletins  upon  milk  production. 

Milk  and  Its  Products.     By  H.  H.  Wing.     The  Macmillan  Co..  New  York. 

Testing  Milk  and  Its  Products.  By  E.  H.  Farrington  and  F.  W.  Woll.  Mendota  Book 
Co.,  Madison,  Wis. 

The  Principles  of  Modern  Dairy  Practice.  By  Gosta  Grotenfelt :  translated  by  F.  W.  Woll. 
John  Wiley  &  Sons,  New  York. 

Elements  of  Dairying.     By  John  W.  Decker.     The  Author.  Columbus,  Ohio. 

The  Chemistrv  of  Dairvine.    Bv  Harry  Snyder.    The  Chemical  Publishing  Co..  East  on,  Pa. 


L2 

Milk  '.\    Kdward    F.    Willuiighbv.     .1.    B.    Lippiixu 

Philadelphia. 

Handbook  f oi  !  ■.■    era  and  Dairymen     Bjj  F,W.WolL    John  Will  \«u  V<»rk. 

Feeds  ttiul   !'.♦,  ling.       B\    \V     A  .Henry.      The  Alll  hoi  ,  Madison ,  \\ 

The  Feeding  of  Annuals.    By  Whitman  Boward  Jordan.    The  afacmulau  Oo  .  Ne*  York. 
Manual  of  Oattl  By  Henry  ftantias  Armaby.    Join  Wiley  &  8one,  New  York. 

The  Book  of  the  Daily.    Bj  W.  Fletschmann;  translated  byC.  aXAikmanand  K.  Patrick 
Wright.     Blakie  A  Son,  Ltd.,  London. 
Milk:  It-  Nature  and  Composition.     By  C:  M.  Aikman.     Adam  lV  Charles  Black,  London. 
Bacteriology  of  Milk.     By  Harold  Swithmbank  and  Geofgi    Newman.    John  Murray, 

London. 

The  Udder  of  the  Oow.     Indiana  >ta.  Bui  62,  VoL  \  II. 
Studies  in  Milk  Set  ration.     New  York  Cornell  Sta.  Bui  160. 
Teating  Oowi  al  the  lam..     WiaoonaiD  Sta.  Bui.  75. 

The  Constitution  <»f  Milk  with  Special  Reference  to  Cheese  Production.     Wiscons!: 
Bui.  til. 

Investigations  Relating  to  the  Manufacture  of  Cheese,  V.     New  York  State  Sta.  Bui 

Kconoinii  al  Met  hods  for  Improving  the  Keeping  Qualities  of  Milk.     Maryland  Sta.  Bui.  S& 

Preventing  Contamination  of  Milk.     Illinois  Sta.  Bui.  91. 

Ropiness  in  Milk  and  Cream.     New  York  Cornell  Sta.  Bui.  195. 

Tainted  or  Defective  Milks;  the  Causes  and  Methods  of  Prevention.     Wisconsin  Sta.  Bui. 
62. 

An  Enquiry  <  oncerning  the  Source  of  (las  and  Taint-produeing  Bacteria  in  Cheese  Curd. 
New  York  Cornell  Sta.  Bui.  158. 

Tables  for  Computing  Rations  for  Farm  Animals.     New  York  Cornell  Sta.  Bui.  164. 


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